Sweeney A W, Doggett S L, Piper R G
Army Malaria Research Unit, Ingleburn, New South Wales, Australia.
J Invertebr Pathol. 1990 May;55(3):428-34. doi: 10.1016/0022-2011(90)90087-m.
The life cycle of Amblyospora indicola, a parasite of the mosquito Culex sitiens, was revealed by field observations and laboratory infection experiments conducted in Australia. In northern Queensland, infected C. sitiens larvae were often found breeding in association with two cyclopoid copepods: Apocyclops dengizicus and an undescribed species of the same genus. The latter species was found to be an intermediate copepod host of this microsporidium whereas A. dengizicus was not. One complete cycle of the parasite extends over two mosquito generations (by transovarial transmission from females with binucleate spores to their eggs) and by horizontal transmission between mosquitoes and copepods. The latter involves horizontal transmission from mosquitoes to copepods via meiospores produced in larval fat body infections and horizontal transmission from copepods to mosquitoes via uninucleate spores produced within infected copepods. Uninucleate clavate spores were formed in Apocyclops sp. nov. copepods 7-10 days after exposure to larval meiospores and were infectious to larvae of a microsporidian-free colony of C. sitiens. The development of A. indicola within mosquito larvae exposed to infected copepods is similar to that of A. dyxenoides infecting C. annulirostris. It proceeds from stages with a single nucleus to diplokaryotic binucleate cells in oenocytes. These stages persist through pupation to adult emergence after which time a proportion of male mosquitoes and female mosquitoes may develop binucleate spores without the need for a blood meal. A proportion of both male and female larval progeny of infected females with binucleate spores develop patent fat body infections via transovarial transmission and die in the fourth larval instar.(ABSTRACT TRUNCATED AT 250 WORDS)
澳大利亚通过野外观察和实验室感染实验，揭示了库蚊的寄生虫——印度微孢子虫的生命周期。在昆士兰北部，经常发现受感染的尖音库蚊幼虫与两种剑水蚤类桡足动物一起繁殖：登氏伪镖水蚤和同一属的一个未描述物种。发现后一种物种是这种微孢子虫的中间桡足动物宿主，而登氏伪镖水蚤不是。寄生虫的一个完整周期跨越两代蚊子（通过双核孢子的雌蚊经卵传递给它们的卵）以及蚊子和桡足动物之间的水平传播。后者包括通过幼虫脂肪体感染产生的减数孢子从蚊子到桡足动物的水平传播，以及通过受感染桡足动物体内产生的单核孢子从桡足动物到蚊子的水平传播。暴露于幼虫减数孢子7 - 10天后，新种伪镖水蚤桡足动物中形成了单核棒状孢子，这些孢子对无微孢子虫的尖音库蚊幼虫具有感染性。暴露于受感染桡足动物的蚊子幼虫体内印度微孢子虫的发育与感染环喙库蚊的迪氏微孢子虫相似。它从单核阶段发展到oenocytes中的双核双核细胞阶段。这些阶段持续到化蛹和成虫羽化，之后一部分雄蚊和雌蚊可能无需取食血液就发育出双核孢子。具有双核孢子的受感染雌蚊的一部分雄性和雌性幼虫后代通过经卵传递形成明显的脂肪体感染，并在第四龄幼虫期死亡。（摘要截取自250字）
